package com.hmdp.utils;

import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.yaml.snakeyaml.events.Event;

import java.util.Collections;
import java.util.UUID;
import java.util.concurrent.TimeUnit;

public class SimpleLock implements ILock {
    private String name;
    private StringRedisTemplate stringRedisTemplate;
    private static final String KEY_PREFIX="lock:";
    private static final String ID_PREFIX= UUID.randomUUID()+"-";
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;
    static {
        UNLOCK_SCRIPT=new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    public SimpleLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }


    @Override
    public boolean tryLock(Long timeoutSec) {
        String threadId = ID_PREFIX+Thread.currentThread().getId();
        Boolean flag = stringRedisTemplate.opsForValue().setIfAbsent(KEY_PREFIX + name , threadId, timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(flag);
    }

    @Override
    public void unlock() {
        //调用lua脚本
        stringRedisTemplate.execute(UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX+Thread.currentThread().getId());
    }

    /*@Override
    public void unlock() {
        String curId = ID_PREFIX + Thread.currentThread().getId();
        String preId = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
        if (curId.equals(preId)) {
            stringRedisTemplate.delete(KEY_PREFIX + name);
        }
    }*/
}
